I guess the best way to put it is, there are no rules except putting anyone down or being nasty will not be tolerated. You can start your socks anytime you wish and there is no set date for completion. I want this to be something you enjoy working on and not add any pressure. I don't think variegated yarn will work with this pattern but a colourway that is has the same colour tones will work. For example, I just started the Campanula for the Cure socks and I am using Tofutisie in colour Light Foot, no. 730 shown on the left. The colour is basically pink, as you can see, but it's not a solid pink. Something like that would work for the Branched Fern but something that has a lot of different colours the pattern would get lost. That doesn't mean it shouldn't be done. It's whatever you prefer. The socks were designed for solid sock yarn. It was what the contest was all about.
Have fun everyone and if any help is needed just shout. I'll join you all in a few weeks after I finish the stuff I am working on.